The Seismic Cassette Hub utilises a unique internal mechanism, which Eclat worked on for the past few years called TCS (Toothed Coupling System). Inspired by systems used on high-end road and mountain bikes, they managed to re-design this system to work inside a BMX cassette hub with a 14mm axle and a 9t driver, something which was never thought possible until now. Instead of the typical pawl based cassette hub, the Seismic hub uses 2 coupled toothed ratchet rings, which are inside the hub and the driver. The 2 rings are pushed together with a very special design of spring, which allows the hub to transfer power in one direction, and “freewheel” in the other. In a nutshell, it’s a much stronger internal mechanism, which can’t fail even after years of heavy use. No more skipping, slipping or popping, you can really crank this thing as hard you want and it’s not going to fail. Even after years of heavy use, this hub was designed to keep going on and on. The Seismic is laced to Eclat's E440 rim. Lightweight at just 440g with a strong double walled design, The Eclat E440 has the edge over the competition. The tall profile provides rigidity while the straight side walls provide added assistance if you're running brakes. ###section### Product Specs WHEEL SIZE:20" HUB:Eclat Seismic AXLE:14mm Male DRIVE SIDE:Right Side Drive RIM:Eclat E440 SPOKES:Stainless Steel NIPPLES:Brass WEIGHT:TBC Colour: Black; Size: RHD